构成商品交易的一个基本前提是有供需双方,而市场经济的建立,则是为供需双方的交易建立规则和提供平台。在这里,买和卖是同样重要的,发扬契约精神,维护双方的合法利益就是市场经济的前提。在证券市场上,人们习惯以多空来代表参与交易的两方,看多者在操作行为上是买入,看空者则是卖出。由于证券交易具有流动性强、价格变化快的特点,因此在实践中,买卖双方的角色是经常变换的,在高频交易中甚至是随时 One of the basic prerequisites for constituting a commodity transaction is the existence of both supply and demand. The establishment of a market economy is to establish rules and provide a platform for the transaction between supply and demand parties. Here, buying and selling are equally important. Carrying forward the spirit of the contract and safeguarding the legitimate interests of both parties is the prerequisite for a market economy. In the securities market, people are accustomed to long and short to represent the two sides involved in the transaction, to see more people in the operating behavior is to buy, the bear is sold. Because securities trading has the characteristics of strong liquidity and rapid price changes, in practice, the roles of buyers and sellers are constantly changing, and even in high-frequency trading at any time